From what I read it seems like your biggest problem is your room.
It is a square room, which will screw up most your frequencies.
Put bass traps (floor to ceiling) in all the corners and to wall ceiling corners.
Hi/Mid absorbers on the sidewalls of your sitting position (using the mirror trick)
There are a few acoustics forums that you can learn a lot from.
I don’t think your gear is the problem.
You can get good results even with a 4-track cassette PortaStudio once you tune (flatten) your room.